Tank car

ABSTRACT

A hopper-type railroad tank car having a longitudinally extending tank shell supported upon a pair of shortened stub center sill assemblies, one at each end, and a plurality of hopper compartments spaced at intervals along the length of the car. Each hopper compartment communicates with a bottom outlet, cut-out of the tank shell. The inboard edges of the center sills are positioned outboard of the respective end-most hopper outlets. An end reinforcing structure is provided to transmit horizontal and vertical loads from the center sills to the tank shell and to transmit bending moments applied to the end of the car to the tank shell.

United States Patent 1 Bembridge et al.

[ 51 Jan.30, 1973 54] TANK CAR [75] lnventors: Henry Bembridge, Oakville, On-

tario; Geoffrey C. Venn-Brown, Cooksvillc, Ontario, both of Canada [73] Assignee: Procor Limited, Oakville, Ontario,

Canada [22] Filed: June 16, 1971 [21] Appl. No.: 153,719

[52] U.S. Cl. ..l05/3S8, 105/248, 105/362, 105/410, 105/413 [51] Int. Cl ...B6ld 5/02, Bold 5/06 [58] Field of Search ..105/358-362, 404, 105/410, 413, 425, 248

[56] References Cited UNITED STATES PATENTS 3,528,375 9/1970 Trausch ..l05/358 3,470,829 l0/l969 Szala ..l05/362 Primary Examiner-Gerald M. Forlenza Assistant Examiner-Richard A. Bertsch Attorney-Charles M. Kaplan et al.

[57] ABSTRACT A hopper-type railroad tank car having a longitudinally extending tank shell supported upon a pair of shortened stub center sill assemblies, one at each end, and a plurality of hopper compartments spaced at intervals along the length of the car. Each hopper compartment communicates with a bottom outlet, cut-out of the tank shell. The inboard edges of the center sills are positioned outboard of the respective end-most hopper outlets. An end reinforcing structure is provided to transmit horizontal and vertical loads from the center sills to the tank shell and to transmit bending moments applied to the end of the car to the tank shell.

18 Claims, 4 Drawing Figures ,PAlENTEnJAnso'lsrs SHEET 1 BF 2 lNVENTORS GEOFFREY c. VE/WV -BROWN HENRY BEM8R/D6E BY 6: M

ATTORNEY PATENTEUmao I875 3.713.399

SHEET 2 BF 2 INVENTORS GEOFFREY C. l/ENN-BROW/V HENRY BEMBR/DGE I 4 ORNEY TANK CAR BACKGROUND OF THE INVENTION This invention relates to railroad tank cars and more particularly to an improved end reinforcing structure for use in railroad tank cars generally of the hoppertype.

Hopper-type railroad tank cars have heretofore included a pair of stub center sill assemblies, associated with the respective ends of the tank shell, which have extended inboard beyond the two end hopper compartments. This structural arrangement has been necessary to permit the car to handle the A. A. R. coupler loads, side bearing loads and jacking loads. Since the center sills have extended inboard beyond the end hopper compartments it has been necessary to raise the two end compartments to a level above the intermediate compartments to prevent interference with the center sills. This has resulted in the following problems: reduced product capacity; precludes the utilization of removable aeration equipment; and causes inaccessibility to the end hopper compartments, which results in assembly, cleanout, maintenance and operation difficulties. It further requires the use of a bent discharge pipe which causes clean-out difficulties and other problems when handling abrasive products.

It has been found from experience, that on railroad tank cars the introduction of horizontal forces at the joint between the draft sills and the tank shell causes considerable creep in the shell at the inboard tip of the sills and that the amount of creep depends on the length of the joint. In order to permit the two end compartments to be positioned at the same level as the intermediate compartments it is necessary to reduce the length of the center sills and thus considerably reduce the length of the center sill/shell joint. This reduction joint length causes severe problems in and around the end-most compartments and their reinforcing plates. The reinforcing structure of the present invention is specifically designed to solve these problems.

SUMMARY OF THE INVENTION It is the principle object of the present invention to provide a hopper-type railroad tank car which permits easy access to the end hopper compartments.

Another object is to provide a hopper-type railroad tank car having its end-most hopper compartments at the same level as its intermediate hopper compartments to facilitate assembly, clean-out, maintenance and operation.

A further object is to provide a hopper-type railroad tank car which permits the utilization of removable aeration equipment at the end-most hopper compartments.

A still further object of the present invention is to provide a railroad tank car, having shortened draft sills, that is capable of carrying A. A. R. coupler loads, sidebearing loads and jacking loads.

Another object is to provide a railroad tank car that includes an end reinforcing structure which transmits horizontal and vertical loads from the center sill to the tank shell and which transmits bending moments applied to the end of the car to the tank shell.

The present invention provides a railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sill assemblies, one at each end, and a plurality of hopper compartments spaced at intervals along the length of the car. Each hopper compartment communicates with a bottom hopper outlet, cutout of the tank shell. The inboard edges of the center sills are positioned outboard of the respective endmost hopper outlets to permit easy access thereto.- A unique end reinforcing structure is provided to transmit horizontal and vertical loads from the draft sill to the tank shell and to transmit bending moments applied to the end of the car to the tank shell. The end reinforcing structure comprises: a pair of longitudinally extending stiffener assemblies attached to the tank shell, one on each side of the center sill assembly; a transversely extending outboard box-section attached to the tank shell adjacent the end portion thereof .and a transversely extending inboard box-section attached to the tank shell positioned inboard of the first box'section and outboard of the end hopper, outlet; a pair of outboard load carrying members, having opposite slopes, diagonally extending upward and outwaRdly from the tank shell portion adjacent the center sill to a pair of opposing points on the tank shell, such that a vertical plane passes through the outboard members and the outboard box-section; and a pair of inboard load carrying members extending upward and outwardly from the tank shell portion adjacent the center sill and the inboard box-section to the pair of opposing points on the tank shell. The outboard and inboard box-sections and the tank shell therebetween form a curved shear girder to receive a horizontal load and distribute it to the tank shell via the longitudinally extending stiffener assemblies. The outboard load carrying members and the inboard load carrying members act as a torsion box to transmit bending moments to the tank shell.

DESCRIPTION OF THE DRAWINGS Other objects and features of the invention will become apparent to those skilled in the art as the disclosure is made in the following description of a preferred embodiment of the invention, as illustrated in the accompanying sheets of drawings, in which:

FIG. 1 is a side elevational view of a hopper-type railroad tank car illustrating an end portion embodying features of the present invention;

FIG. 2 is a perspective view of the end portion of the tank car of FIG. 1 showing the unique end reinforcing structure of the present invention;

FIG. 3 is a vertical sectional view taken along line 33 in FIG. 2 illustrating one of the longitudinally extending stiffeners and a portion of the inboard box-section; and

FIG. 4 is a vertical sectional view taken along line 4-4 in FIG. 2 illustrating the structural connections between the inboard and outboard load carrying members and the inboard and outboard box-sections.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, there is shown a hopper-type railroad tankcar generally designated by the numeral 10. The tank car 10 is preferably comprised of a reinforced, relatively thin shelled tank 11 that serves as the confining enclosure for a conventional hopper structure 12. Hopper structure 12 includes a plurality of generally conically shaped hopper compartments 13. The structural details are substantially identical for cars having from three to seven hopper compartments, except for the number of hoppers. The reinforced tank 1 1 is supported at its'opposite ends by a combined draft rigging and body bolster assembly 14. Assembly 14 functions both as the supporting means for the ends of the tank 11 and as the means for linkingthe tank to conventional truck assemblies 15.

Each of the assemblies 14 includes a pair of spaced apart support channels or center sills 16. The center sills 16 provided at each end of the tank 1 1, are secured to a tank reinforcing plate 17 which is welded or other wise secured to the underside of the tank adjacent the corresponding end thereof. Aligned peripheral side portions at each end of the tank 11 are reinforced by suitable saddle plates 18 that are preferably integrally secured to the tank. These saddle plates 18 extend from adjacent the reinforcing plates 17 to a location approximately midway up the sides of the tank, and the plates 18 cover a sufficient area so that local stress concentration in the tank shell is minimized. It will be appreciated that the draft gears, truck assemblies, and other conventional components typically employed in railroad tank cars would be suitably joined to the aforedescribed tank supporting structure to complete the carfor operation. A rear draft stop 25 secured to the inner surfaces of center sills 16 abuts the rear end of the draft gear and coupler structure (not shown) and transmits forces to the center sills 16 from the draft gear and coupler structure upon buff and impact loads exerted against the coupler.

Each of the hoppers 13, which are defined by plate members 19 that are welded or otherwise suitably secured to the internal surface of tank 11, communicates with a lower discharge outlet port 20 cutout of the bottom of shell 11. All of the outlet ports 20 are substantially at the same level to maximize commodity capacity and facilitate assembly, clean-out, maintenance and operation. As seen in FIG. 1, the center sills 16 at each end of tank shell 11 are shortened such that their inboard edges are positioned outboard of the adjacent end-most hopper outlets 20. This reduction in center sill length, and the consequential reduction in center sill/shell joint,'tends to cause considerable creep in the shell at the inboard tip of the sill, which results in severe problems in the welds in and around the endmost hopper outlets 20.

In accordance with the present invention, an end reinforcing structure 30 is provided at each end of tank car which transmits horizontal and vertical loads from the center sill assemblies 16 to the tank shell '11 and which transmits bending moments applied to the end of the car to the tank shell 11. As shown in FIGS. 2-4 reinforcing structure 30 includes: a pair of longitudinally extending stiffener assemblies 32 and 33; inboard and outboard transversely extending box-sections 34 and 36 respectively; a pair of outboard load carrying members 37 and 38; and a pair of inboard load carrying members39 and 40l Re'ferring to FIGS. 2and 3, stiffener assemblies 32 and 33 each include longitudinally extending internal and external angle stiffeners 60 and 61 respectively, secured to and sandwiching shell 11 therebetween in a suitable manner, as by welding. Stiffeners 60 and 61 preferably extend from approximately the tank line to a point inboard of the endmost outlets 20. Stiffener assemblies 32 and 33 are parallel to center sill assemblies 16, one on each side thereof, and are spaced apart by a distance greater than the outer dimension of the end-most hoppers 20.

Referring to FIGS. 2 and 4, inboard box-section 34 includes a transverse channel shaped member 41, which is positioned on the bottom surface of shell 11 and extends between stiffener assemblies 32 and 33 and is slightly outboard of the end-most outlets 20. End plates 42 close off the open ends of member 41 and are suitably secured to internal stiffeners 41. Outboard box-section 36 includes a transverse angle member 43 which is positioned on the bottom surface of shell 11 and extends between stiffener assemblies 32 and 33, and is positioned approximately at the tan line of tank car 10. The tank head and tank shell close off member 43 to form a box-section 36 similar to box-section 34. End plates 44 close off the open ends of member 43 and are sutiably secured to internal stiffeners 41. Backup bars 35 may be provided to reinforce the structural connection between the bottom surfaces of box-sections 34 and 36 and the inner surface of shell 11;

Outboard load carrying members.37 and 38 each include a tubular pipe section 45 and 46 respectively, extending upward and outward from the tank shell portion adjacent center sills 16. Pipes 45 and 46 have opposite slopes and are spaced a greater distance apart at their upper ends than at their lower ends, as seen in FIG. 2. The lower ends of pipes 45 and 46 are respectively secured to gusset plate 47 and 48 which in turn pass through box-section 36 and are secured to tank shell 1 1, one immediately above each of the center sills 16. A substantially vertical plane passes through members 37 and 38 and box-section 36. The upper ends of pipes 45 and. 46 are respectively secured to gusset plates 49 and 50 which in turn are respectively secured to a pair of opposing points on tank shell 11. Reinforcing plates 51 and 52 are provided at the points where plates 49 and 50 are attached to shell 11, which are approximately midway up the tank sidewalls. A transverse pipe '59, attached at its respective ends to gussets 49 and 50, extends between the upper ends of members 37 and 38.

Inboard load carrying members 39 and 40 each include a tubular pipe section 53 and 54 respectively, extending upward and outward from a portion of the tank shell adjacent center sills l6 and the box-section 34, to plates 51 and 52 respectively. The lower ends of pipes 53 and 54 are respectively secured to gusset plates 55 and 56 which in turn pass through box-section 34 and are secured to tank shell 11, one immediately above each of the center sills 16. The upper ends of pipes 53 and 54 are respectively secured to gusset plates 57 and 58 which are in turn respectively secured to reinforcing plates 51 and 52.

Referring to FIG. 4, the load paths of the forces upon impact loads are. illustrated by appropriatearrows. A moment arm M exists between the center line of the rear draft stop 25 and the weld between the shell 11 and sills 16 upon the introduction of longitudinal loads at stop 25. The reaction to the longitudinal load occurs at the weld between shell 11 and sills 16. This moment causes a tensile force in outboard load carrying members 37 and 38 transmitted from center sills 16 via plates 47 and 48. Resulting reaction forces appear in inboard load carrying members 39 and 40 and pass to the sills 16 via plates 55 and 56; Because the inboard load carrying members and the outboard load carrying members are positioned so that their center line intersect at plates 51 and 52, both the vertical and transverse components of the forces cancel each other out at this point. The remaining component is longitudinal, and is transmitted to shell 11 via plates 57 and 58 and plates 51 and S2. Transverse pipe 59 theoretically carries no structural loads, but is included for stiffening purposes and to carry any structural loads resulting from construction eccentricities. Outboard load carrying members 37 and 38 and inboard load carrying members 39 and 40 act as a torsion box so as to transmit bending moments to tank shell 11.

Horizontal longitudinal loads that are applied to car at the joint between sills 16 and shell 11 are distributed to the tank shell 11 by a resulting shear girder made up of box-sections 34 and 36 and the portion of shell 11 therebetween. Most of the load is removed from the portion of shell 11 between box-sections 34 and 36 and distributed to a larger portion of shell 11 by stiffener assemblies 32 and 33. As seen in FIG. 3 stiffener assemblies 32 and 33 each include angle stiffeners 61 and 62 sandwiching shell 11 therebetween. In this arrangement, the neutral axis of the stiffeners 32 and 33 in the plane of shell 11 coincides with shell 11, where the load is applied and removed by the stiffeners 32 and 33. Thus, there will be no major bending moments applied to stiffeners 32 and 33.

Although the preferred embodiment is disclosed in conjunction with a hopper-type railroad tank car it is contemplated that end reinforcing structure 30 of the present invention is equally applicable for use in conventional railroad tank cars to transmit horizontal and vertical loads from the center sill to the tank shell and to transmit bending moments applied to the end of the car to the shell. Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

What is claimed is:

1. In a railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end; an improved end reinforcing structure to transmit horizontal and vertical loads from the center sill to the tank shell, comprising:

a. a pair of longitudinally extending stiffener assemblies attached to said tank shell, one on each side of said center sill;

b. a first transversely extending structural member attached to said shell adjacent the end portion thereof and a second transversely extending structural member attached to said tank shell positioned inboard of said first structural member;

0. a pair of outboard load carrying members, having opposite slopes extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first structural member; and

. a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second structural member to said pair of opposing points on said tank shell;

e. said first and second structural members and the tank shellportion, therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies;

f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.

2. The invention of claim 1 further including a transverse structural member attached at its ends to said opposing points of said tank shell.

3. The invention of claim 1 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second structural member and are secured to said tank shell immediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first structural member and are secured to said tank shell immediately above said center sill.

4. The invention of claim 3 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points.

5. The invention of claim 4 wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points.

6. The invention of claim 1 wherein each of said stiffener assemblies includes an internal angle stiffener member secured to the internal surface of said shell and external angle stiffener member secured to the external surface of said shell, said internal stiffener member and said external stiffener member sandwich a portion of said shell therebetween.

7. ln a hopper-type railroad tank car including a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end; a plurality of hopper compartments spaced at intervals along the length of said tank shell, each communicating with a bottom hopper outlet cut-out of said tank shell, the inboard edges of said center sills being positioned outboard of the respective endmost hopper outlets to permit said hopper outlets to be positioned all at substantially the same level; and end reinforcing structure means associated with each end of said tank shell to transmit horizontal and vertical loads from said center sill to said tank shell; said end reinforcing structure comprising:

a. a pair of longitudinally extending stiffener assemblies attached to said tank shell; one on each side of said center sill;

. a first transversely extending box-section attached to said tank shell adjacent the end portion thereof and a second transversely extending box-section attached to said tank shell positioned inboard of said first box-section and outboard of said end hopper outlet;

c. a pair of outboard load carrying members, having opposite slopes, extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first boxsection; and

a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second box-section to said pair of opposing points on said tank shell;

. said first and second box-sections and the tank shell therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies;

f. said outboard load carryingmembers and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.

8. The invention of claim 7 further including a transverse structural member attached at its ends to said opposing points of said tank shell.

9. The invention of claim 7 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second box-section and are secured to said tank shell immediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first box-section and are secured to said tank shell immediately above said center sill.

10. The invention of claim 9 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points.

11. The invention of claim wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points.

12. The invention of claim 7 wherein each of said stiffener assemblies includes an internal angle stiffener member secured to the internal surface of said shell and an external angle stiffener member secured to the external surface of said shell, said internal stiffener member and said external stiffener member sandwich a portion of said shell therebetween.

13. in a hopper-type railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end, and a plurality of hopper compartments spaced at intervals along the length of said tank shell each communicating with a bottom hopper outlet cut-out of said tank shell, the inboard edges of said center sills being positioned outboard of the respective end-most hopper outlets; an improved and reinforcing structure, to transmit horizontal and vertical loads from the center sill to the tank shell, comprising:

a. a pair of longitudinally extending stiffener assemblies attached to said tank shell, one on each side of said center sill; a first transversely extending structural member attached to said tank shell adjacent the end portion thereof and a second transversely extending structural member attached to said tank shell positioned inboard of said first structural member and outboard of said end hopper outlet;

. a pair of outboard load carrying members, having opposite slopes extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first structural member; and I a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second structural member to said pair of opposing points on said tank shell;

. said first and second structural members and the tank shell portion therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies;

f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.

14. The invention of claim 13 further including a transverse structural member attached at its ends to said opposing points of said tank shell.

15. The invention of claim 13 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second structural member and are secured to said tank shellimmediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first structural. member and are secured to said tank shell immediately above said center sill.

16. The invention of claim 15 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points. v

17. The invention of claim 16 wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points.

18. The invention of claim 13 wherein each of said stiffener assemblies includes an internal angle stiffener member secured to the internal surface of said shell and an external angle stiffener member secured to the external surface of said shell, said internal stiffener member and said external stiffener member sandwich a portion of said shell therebetween. 

1. In a railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end; an improved end reinforcing structure to transmit horizontal and vertical loads from the center sill to the tank shell, comprising: a. a pair of longitudinally extending stiffener assemblies attached to said tank shell, one on each side of said center sill; b. a first transversely extending structural member attached to said shell adjacent the end portion thereof and a second transversely extending structural member attached to said tank shell positioned inboard of said first structural member; c. a pair of outboard load carrying members, having opposite slopes extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first structural member; and d. a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second structural member to said pair of opposing points on said tank shell; e. said first and second structural members and the tank shell portion therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies; f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.
 1. In a railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end; an improved end reinforcing structure to transmit horizontal and vertical loads from the center sill to the tank shell, comprising: a. a pair of longitudinally extending stiffener assemblies attached to said tank shell, one on each side of said center sill; b. a first transversely extending structural member attached to said shell adjacent the end portion thereof and a second transversely extending structural member attached to said tank shell positioned inboard of said first structural member; c. a pair of outboard load carrying members, having opposite slopes extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first structural member; and d. a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second structural member to said pair of opposing points on said tank shell; e. said first and second structural members and the tank shell portion therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies; f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.
 2. The invention of claim 1 further including a transverse structural member attached at its ends to said opposing points of said tank shell.
 3. The invention of claim 1 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second structural member and are secured to said tank shell immediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first structural member and are secured to said tank shell immediately above said center sill.
 4. The invention of claim 3 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points.
 5. The invention of claim 4 wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points.
 6. The invention of claim 1 wherein each of said stiffener assemblies includes an internal angle stiffener member secured to the internal surface of said shell and external angle stiffener member secured to the external surface of said shell, said internal stiffener member and said external stiffener member sandwich a portion of said shell therebetween.
 7. In a hopper-type railroad tank car including a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end; a plurality of hopper comparTments spaced at intervals along the length of said tank shell, each communicating with a bottom hopper outlet cut-out of said tank shell, the inboard edges of said center sills being positioned outboard of the respective endmost hopper outlets to permit said hopper outlets to be positioned all at substantially the same level; and end reinforcing structure means associated with each end of said tank shell to transmit horizontal and vertical loads from said center sill to said tank shell; said end reinforcing structure comprising: a. a pair of longitudinally extending stiffener assemblies attached to said tank shell; one on each side of said center sill; b. a first transversely extending box-section attached to said tank shell adjacent the end portion thereof and a second transversely extending box-section attached to said tank shell positioned inboard of said first box-section and outboard of said end hopper outlet; c. a pair of outboard load carrying members, having opposite slopes, extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first box-section; and d. a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second box-section to said pair of opposing points on said tank shell; e. said first and second box-sections and the tank shell therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies; f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.
 8. The invention of claim 7 further including a transverse structural member attached at its ends to said opposing points of said tank shell.
 9. The invention of claim 7 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second box-section and are secured to said tank shell immediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first box-section and are secured to said tank shell immediately above said center sill.
 10. The invention of claim 9 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points.
 11. The invention of claim 10 wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points.
 12. The invention of claim 7 wherein each of said stiffener assemblies includes an internal angle stiffener member secured to the internal surface of said shell and an external angle stiffener member secured to the external surface of said shell, said internal stiffener member and said external stiffener member sandwich a portion of said shell therebetween.
 13. In a hopper-type railroad tank car having a longitudinally extending tank shell supported upon a pair of stub center sills, one at each end, and a plurality of hopper compartments spaced at intervals along the length of said tank shell each communicating with a bottom hopper outlet cut-out of said tank shell, the inboard edges of said center sills being positioned outboard of the respective end-most hopper outlets; an improved and reinforcing structure, to transmit horizontal and vertical loads from the center sill to the tank shell, comprising: a. a pair of longitudinally extending stiffener assemblies attached to said tank shell, one on each side of said centEr sill; b. a first transversely extending structural member attached to said tank shell adjacent the end portion thereof and a second transversely extending structural member attached to said tank shell positioned inboard of said first structural member and outboard of said end hopper outlet; c. a pair of outboard load carrying members, having opposite slopes extending upward and outward from said tank shell portion adjacent said center sill to a pair of opposing points on said tank shell, such that a substantially vertical plane passes through said outboard members and said first structural member; and d. a pair of inboard load carrying members extending upward and outward from said tank shell portion adjacent said center sill and said second structural member to said pair of opposing points on said tank shell; e. said first and second structural members and the tank shell portion therebetween forming a curved shear girder to receive a horizontal load and distribute it to said tank shell via said longitudinally extending stiffener assemblies; f. said outboard load carrying members and said inboard load carrying members acting as a torsion box so as to transmit bending moments to said tank shell.
 14. The invention of claim 13 further including a transverse structural member attached at its ends to said opposing points of said tank shell.
 15. The invention of claim 13 wherein said outboard load carrying members and said inboard load carrying members each have connector plates associated with their respective ends, said connector plates associated with the bottom ends of said outboard load carrying members pass through said second structural member and are secured to said tank shell immediately above said center sill, and said connector plates associated with the bottom ends of said inboard load carrying members pass through said first structural member and are secured to said tank shell immediately above said center sill.
 16. The invention of claim 15 wherein said connector plates associated with the tops ends of said outboard load carrying members and said inboard load carrying members are secured to said tank shell at said opposing points.
 17. The invention of claim 16 wherein a wear plate is secured to said tank shell at said opposing points to receive said connector plates secured to said tank shell at said opposing points. 